Difficulty level of changing electircal motor bearings?

[Mark Henshaw]

Have a Grizzly 00733 lathe with a 2 hp variable speed drive. The input to the drive is 220v single phase but the output to the motor is 3 phase. The lathe is out of its warrantee period and is starting to show signs of a front motor bearing going bad. Anybody have experience with replacing one of these bearings? Is this something that can be readily performed by a non-professional or should i just take it to a motor shop and get a quote? Any advice by people who have tried this would be appreciated.

[David Kumm]

I haven't changed that one specifically but a lot of bearings over the years. Bearing pullers are cheap and a 100w light bulb will usually work to heat the new bearing. Pretty easy but don't pound on the new one to put it on unless you only apply pressure to the inside shoulder. Better to apply heat than hammer. Dave

[Bruce Wrenn]

I agree with Dave. Auto part stores rent/lend bearing pullers. When you heat bearing on top of light bulb, be sure and wear leather gloves as it will be too hot to handle. As a side note, Dollar Tree now stocks 100 watt rugged service bulbs.

[Glenn Samuels]

As someone who is not mechanically inclined, I took my 3 HP from my Grizzly Table Saw to a machine shop. Seems that my 20 year old motor used open bearings so sawdust got into them. Now it has sealed bearings and it hums like a dream.

[David Kumm]

As someone who is not mechanically inclined, I took my 3 HP from my Grizzly Table Saw to a machine shop. Seems that my 20 year old motor used open bearings so sawdust got into them. Now it has sealed bearings and it hums like a dream.

Open bearings are often superior to sealed but generally not in a motor unless used by someone who knows not to overgrease. I've seen motors completely full of excess grease in the windings yet they still run. Dave

[HANK METZ]

I haven't changed that one specifically but a lot of bearings over the years. Bearing pullers are cheap and a 100w light bulb will usually work to heat the new bearing. Pretty easy but don't pound on the new one to put it on unless you only apply pressure to the inside shoulder. Better to apply heat than hammer. Dave

Old timers would place a few drops of water on the bearing, heating it just until the water bubbled, then apply.
Here's a video (https://www.youtube.com/watch?v=hrGG_kIz2Zk)doing about the same thing.

As Dave said, always apply force to the inner race, never the out.

[jack forsberg]

motor bearing in a 3 phase motor are so easy to do a monkey could do it. The light bulb is the way . bearing are a press on the shaft and slip fit in the end bells. mark your end bells before you take the motor apart so you know how them go back together. cheap pullers is all you really need. Here is how i use a light bulb to sweat on a bearing


https://www.youtube.com/watch?v=ocsnUBYEyuM&list=UUI6jpIs2zjN9DmVvK2ZAWXA

[HANK METZ]

That's a nice vid Jack, I like the guy's tip about installing with the bearing type # facing out; one can order replacements without dis-assembly first.

[jack forsberg]

That's a nice vid Jack, I like the guy's tip about installing with the bearing type # facing out; one can order replacements without dis-assembly first.

thanks that guy is me.

[HANK METZ]

thanks that guy is me.

And such clean fingernails too! :D